CPU cooling arrangement for portable computer

ABSTRACT

A CPU cooling arrangement for portable computer is constructed to include a heat sink fastened to a CPU in a computer mainframe, the heat sink having two opposite open sides and a plurality of radiation fins defining a convection trough between each two adjacent radiation fins in communication with the open sides, a fan mounted in a fan hole on one sidewall of the computer mainframe, and a wing box coupled between the fan and one open side of the head sink.

BACKGROUND OF THE INVENTION

The present invention relates to a CPU cooling arrangement for portablecomputer and, more particularly, to such a CPU cooling arrangement,which requires less installation space and achieves a high coolingefficiency. The heat sink used in the CPU cooling arrangement provides abroad heat dissipation surface area that dissipates heat quickly fromthe CPU.

In order to make a portable computer compact for carrying, the thicknessmust be made as thinner as possible. A regular computer mainframecomprises a motherboard having a CPU socket and a CPU (centralprocessing unit) installed in the CPU socket. The CPU produces much heatduring its operation. In order to dissipate heat from the CPU, coolingmeans must be used. Conventionally, an aluminum-extruded heat sink isused with a fan in a portable computer to dissipate heat from the CPU.In a notebook computer, the keyboard is provided above the motherboard.There is little space between the keyboard and the motherboard for theinstallation of cooling means. In case a fan is installed, it cannotdirectly draw outside cooling air into the mainframe from the topsidebecause the keyboard blocks the topside of the computer mainframe.According to conventional designs, aluminum heat plates and/or heatpipes are commonly used in notebook computers for dissipation of heatfrom the CPU. These conventional designs cannot efficiently rapidlycarry heat away from the CPU. Further, regular heat sinks for desktopcomputers are less efficient for the drawback of limited heatdissipation surface area. Due to limited heat dissipation surface area,a conventional heat sink cannot achieve the desired heat dissipationeffect even when a fan attached.

FIG. 1 is an exploded view of a CPU cooling structure according to theprior art. This design of CPU cooling structure comprises a heat sink 2fastened to the CPU (central processing unit) 11, and a fan 3 fastenedto the heat sink 2. The heat sink 2 comprises a contact base 21 disposedin contact with the top sidewall of the CPU 11, a plurality of uprightradiation fins 22 upwardly extended from the contact base 21 andarranged in parallel, and a plurality of troughs 23 respectively definedbetween the radiation fins 22. The fan 3 has a plurality of mountingholes 31 respectively fastened to grooves in the heat sink 2 by tiescrews 5. Due to limited heat dissipation surface area of the heat sink2, this design of CPU cooling structure is not satisfactory in function.

SUMMARY OF THE INVENTION

The present invention has been accomplished to provide a CPU coolingarrangement, which eliminates the drawbacks of the conventional CPUcooling designs.

It is therefore the main object of the present invention to provide aCPU cooling arrangement for portable computer, which achieves asatisfactory heat dissipation effect.

According to one embodiment of the present invention, the CPU coolingarrangement comprises a motherboard invertedly fixedly mounted insidethe computer mainframe holding the CPU at the bottom side, a heat sinkmounted on the CPU at the bottom side, and a fan mounted on the heatsink at the bottom side and facing an air hole in the bottom shell ofthe computer mainframe for drawing outside cooling air upwardly into thecomputer mainframe toward the heat sink to carry heat away from the CPUefficiently. According to another aspect of the present invention, theinstallation of the CPU cooling arrangement enables outside cooling airto be directly drawn into the inside of the mainframe shell of thecomputer mainframe to carry heat away from the heat sink and the CPU.According to still another aspect of the present invention, the computermainframe comprises a keyboard disposed at the topside and formed of ametal frame, a circuit board, and a set of key switches, and themotherboard is fixedly fastened with the circuit board of the keyboardto the metal frame of the keyboard.

According to another aspect of the present invention, the computermainframe comprises a liquid crystal display module disposed at thetopside, and the motherboard is fixedly fastened to a bottom sidewall ofthe liquid crystal display module.

According to still another aspect of the present invention, the computermainframe comprises a protruded portion disposed in the bottom shellaround the air hole and adapted to receive the fan. According to stillanother aspect of the present invention, the bottom shell of thecomputer mainframe is a flat shell.

According to still another aspect of the present invention, the heatsink has six sides, the six sides including two opposite open sidesselectively for the mounting of the fan and four close sides, a contactbase formed integral with one of the close sides, a plurality ofradiation fins perpendicularly extended from the contact base andarranged in parallel, the radiation fins each comprising a plurality ofprotruded portions and recessed portions, and at least one convectiontrough respectively defined between the protruded portions and recessedportions of the radiation fins.

According to still another aspect of the present invention, the fourclose sides of the heat sink include a close topside having at least oneair vent disposed in communication with the at least one convectiontrough. Alternatively, the close topside of the heat sink can be madehaving at least one elongated slot disposed in communication with the atleast one convection trough, or having at least one air vent and oneelongated slot disposed in communication with the at least oneconvection trough.

According to still another aspect of the present invention, two fans maybe used and respectively mounted in the two opposite open sides of theheat sink.

According to still another alternate form of the present invention, theCPU cooling arrangement comprises a heat sink mounted on the topsidewall of the CPU, the heat sink having a plurality of peripheralsides, the peripheral sides including a plurality of close sides and twoopposite open sides, the close sides including one forming a contactbase disposed in contact with the CPU, a plurality of radiation finsrespectively perpendicularly extended from the contact base, and atleast one convection trough defined between the radiation fins; a fan;and a wind box, the wind box comprising an inner wind hole disposed inone end thereof and coupled to one open side of the heat sink, an outerwind hole disposed in an opposite end thereof in communication with afan hole in the mainframe shell of the computer mainframe, a fan seatdisposed in the outer wind hole and adapted to receive the fan, and twomounting flanges respectively disposed at top and bottom sides of theouter wind hole, the mounting flanges each having at least one screwhole respectively fastened to a respective screw hole of the mainframeshell with a respective tie screw. The radiation fins of the heat sinkmay be directly perpendicularly connected to the CPU. Further, the windbox can be formed integral with a part of the mainframe shell around thefan hole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a CPU cooling structure according to theprior art.

FIG. 2 is an exploded view of a CPU cooling arrangement for portablecomputer according to the present invention.

FIG. 3 is a sectional assembly view of the CPU cooling arrangementaccording to the present invention.

FIG. 4 is a sectional assembly view of an alternate form of the CPUcooling arrangement according to the present invention.

FIG. 5 is an elevational view of a heat sink for the CPU coolingarrangement according to the present invention.

FIG. 6 is an elevational view showing a fan fixedly fastened to one sideof the heat sink according to the present invention.

FIG. 7 is a schematic drawing showing heat dissipation effect of the CPUcooling arrangement according to the present invention.

FIG. 8 is an elevational view of an alternate form of the heat sink forthe CPU cooling arrangement according to the present invention.

FIG. 9 is an elevational view of another alternate form of the heat sinkfor the CPU cooling arrangement according to the present invention.

FIG. 10 is an exploded view of another alternate form of the CPU coolingarrangement according to the present invention.

FIG. 11 is a perspective view showing the CPU cooling arrangement ofFIG. 10 installed.

FIG. 12 is a side view in an enlarged scale of the CPU coolingarrangement shown in FIG. 11.

FIG. 13 is a top view of FIG. 12.

FIG. 14 is an exploded view of still another alternate form of the CPUcooling arrangement according to the present invention.

FIG. 15 is an exploded view of still another alternate form of the CPUcooling arrangement according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described by way of example withreference to the annexed drawings:

EXAMPLE I

A portable computer CPU cooling arrangement in accordance with the firstembodiment of the present invention is shown in FIGS. 2 and 3. Anall-in-one motherboard 13 is installed in a portable computer mainframe1, or a LCD (liquid crystal display) module 14 (see FIG. 4). Theportable computer mainframe 1 has provided in the topside thereof ametal frame 120, a circuit board 121, and a keyboard 12 having a set ofkey switches 122. The motherboard 13 comprises a CPU socket 20, whichreceives a CPU (central processing unit) 11. On the surface of the CPU11 there are mounted in proper order an aluminum-extruded heat sink 2and a cooling fan 3. Unlike conventional designs, the motherboard 13carrying the heat sink 2 and the cooling fan 3 is invertedly installedin the portable computer mainframe 1. The cooling fan 3 is coupled tothe air vents 100 in the bottom shell 10 of the portable computermainframe 1. The bottom shell 10 can be a flat shell. Alternatively, thebottom shell 10 can be made having a protruded portion 101 in which theair vents are provided (see FIG. 2). Ventilation flanges 102 may beprovided, fitting over protruded electronic component parts, forexample, memory means of the motherboard 13.

Because the high-performance aluminum-extruded heat sink 2 and coolingfan 3 are used with the CPU 11, heat can be quickly carried away fromthe CPU 11. The heat sink 2 has multiple radiation fins, which provide abroad surface area in contact with the air for quick dissipation ofheat. The operation of the cooling fan 3 greatly increases the frequencyof the air striking the aluminum-extruded heat sink 2. Because the heatsink 2 is mounted on the motherboard 13 that is invertedly installed inthe portable computer mainframe 1, the keyboard 12 does not interferewith the operation of the cooling fan 3 to draw outside cooling air intothe inside of the portable computer mainframe 1 through the air vents100 toward the heat sink 2 and the CPU 11, enabling heat to be quicklycarried away from the CPU 11. Therefore, the invention achieves a heatdissipation effect much better than the conventional portable computerheat dissipation designs.

Further, because the motherboard 13 is invertedly mounted in the topsideof the portable computer mainframe 1, the electronic elements of themotherboard 13 are respectively disposed facing the bottom side. Inorder to facilitate the assembly process, the motherboard 13 and thecircuit board 121 of the keyboard 12 use a common metal frame 120, i.e.,the motherboard 13 and the keyboard circuit board 121 are mounted on themetal frame 120, so that the internal space of the mainframe 1 can befully utilized. In FIG. 4, the motherboard 13 is directly mounted in thebottom side of the LCD module 14 to minimize space occupation.

EXAMPLE II

Referring to FIG. 5, the heat sink 2 according to the second embodimentof the present invention comprises a contact base 21, a plurality offishbone-like radiation fins 22 integral with the contact base 21, aconvection trough 23 defined between each two adjacent radiation fin 22.

The heat sink 2 has six sides including two opposite open sides. Theother four sides of the heat sink 2 are closed sides. The radiation fins22 are respectively upwardly extended from the contact base 21. Theradiation fins 22 have protruded and recessed portions, and a convectiontrough 23 is defined in the protruded and recessed space between eachtwo adjacent radiation fins 22. This heat sink design has a broad heatdissipation area to improve heat dissipation efficiency. Because theheat sink 2 has a broad heat dissipation area wider than conventionaldesigns, it transmits heat efficiently.

EXAMPLE III

FIGS. 6 and 7 are perspective and schematic drawings of a thirdembodiment of the present invention, showing the heat sink 2 used withthe cooling fan 3. The cooling fan 3 is fixedly fastened to one openside of the heat sink 2 with tie screws 5. When the temperature of thebottom heat source (CPU) 11 start to produce heat, heat is rapidlytransmitted to the contact base 21 of the heat sink 2 and then to theradiating fins 22, and then dissipated into the convection troughs 23,and at the same time the cooling fan 3 causes currents of air to carryheat away from the convection troughs 23 to the outside of the heat sink2.

Two fans 3 may be provided at the two opposite open sides of the heatsink 2 to carry heat away from the heat sink 2 efficiently. In thiscase, the fans 3 include on suction fan and one exhaust fan.

As indicated, this embodiment efficiently carries heat away from theheat source 11 by means of a broad heat dissipation area. Thisembodiment is practical for the transmission of continuous heat.

EXAMPLE IV

FIG. 8 is an elevational view of the fourth embodiment of the presentinvention. According to this embodiment, the heat sink 2 has at leastone air vent 24 in the top sidewall in communication with the convectiontroughs 23 for quick dissipation of heat.

EXAMPLE V

FIG. 9 is an elevational view of the fifth embodiment of the presentinvention. According to this embodiment, the heat sink 2 has at leastone line of heat dissipation slot 25 cut through the top sidewall ncommunication with the convection troughs 23 for quick dissipation ofheat.

Alternatively, the aforesaid at least one air vent 24 and the at leastone line of heat dissipation slot 25 can be concomitantly provided inthe top sidewall of the heat sink 2 for quick dissipation of heat.

By means of increasing the heat dissipation area of the heat sink andchanging the direction and position of the cooling fan, the inventiongreatly improves the heat dissipation efficiency, and eliminates thedrawbacks of insufficient heat dissipation area and poor heatdissipation effect of the prior art heat sinks.

EXAMPLE VI

FIG. 10 is an exploded view of the sixth embodiment of the presentinvention. This embodiment is comprised of a heat sink 2, a fan 3, and awind box 4. The heat sink 2 is made of heat dissipation material andmounted on the topside of the CPU 11, having six sides including twoopposite open sides and four close sides. The heat sink 2 comprises abottom contact base 21, a plurality of radiation fins 22 upwardlyextended from the contact base 21, and a convection trough 23 defined inbetween each two adjacent radiation fins 22. The fan 3 can be a suctionfan or exhaust fan. The wind box 4 is an air conduit adapted to deliverflows of air, having an outer wind hole 41 in one open side thereof aninner wind hole 42 disposed in the other open side thereof and adaptedto receive one end of the heat sink 2, a fan seat 43 in the outer windhole 41 for the positioning of the fan 3, and two mounting flanges 44respectively disposed at the top and bottom sides of the outer wind hole41. The mounting flanges 44 each have a screw hole 45. The installationprocedure of this embodiment is outlined hereinafter. The heat sink 2 isfixedly fastened to the topside of the CPU 11, and then the fan 3 ispress-fitted into the fan seat 43 in the outer wind hole 41 of the windbox 4, and then the inner wind hole 42 of the wind box 4 is coupled toone end of the heat sink 2, and then the screw holes 45 of the mountingflanges 44 of the wind box 4 are respectively fastened two respectivescrew holes 61 in the mainframe shell 6 by respective tie screws 5,keeping the outer wind hole 43 connected to the fan hole 62 of themainframe shell 6.

FIG. 11 is a perspective view showing the sixth embodiment of thepresent invention installed. As illustrated, the heat sink 2 has anelongated profile attached to the wind box 4. In addition to heatdissipation function, the heat sink 2 simultaneously serves as a heatdissipation air conduit. During the operation of the CPU 11, heat isquickly carried away from the CPU 11 to the outside of the mainframeshell 6. Because the heat sink 2 has an elongated profile, it provides abroad heat dissipation area to dissipate heat from the CPU 11efficiently.

FIGS. 12 and 13 are side view and top view, showing the six embodimentof the present invention installed in the mainframe shell 6. Asindicated, the heat sink 2 has a broad heat dissipation area, howeverthe installation of the CPU cooling arrangement occupies less verticalspace in the mainframe shell 6. The design of the fan 3 is free from thelimitation of the configuration of the CPU 11, i.e., the dimensions andcapacity of the fan 3 can freely be designed as desired.

EXAMPLE VII

FIG. 14 is an exploded view of the seventh embodiment of the presentinvention. According to this embodiment, the radiation fins 22 of theheat sink 2 are directly perpendicularly connected to the surface of theCPU 11, and the extension part of the heat sink 2 forms a wind channel.

EXAMPLE VIII

FIG. 15 is an exploded view of the eighth embodiment of the presentinvention. According to this embodiment, the wind box 63 is directlyformed of a part of the mainframe shell 6 around the fan hole 62 bystamping.

As indicated above, the invention completely changes the conventionalCPU heat dissipation structures. Because the CPU is the operation centerof the computer, the normal functioning of the computer depends on thenormal performance of the CPU. In order to keep the CPU workingnormally, the heat dissipation function of the CPU heat dissipationstructure must be enhanced. Because the CPU heat dissipation operationof the conventional designs runs in the high temperature space withinthe mainframe shell, simply increasing the capacity of the fan cannotsignificantly reduce the temperature of the CPU. The technical contentsand measures of the aforesaid embodiments of the present invention breakthrough the bottleneck encountered in the conventional designs. Theinvention greatly increases the heat dissipation area, and expels heatfrom the area surrounding the CPU to the outside of the mainframe shell,or guides outside cooling air into the inside of the mainframe shell tolower the temperature of the CPU effectively.

The invention extends the length of the heat sink to the mainframeshell, and uses a wind box to hold the fan, enabling outside cooling airto be sucked into the inside of the mainframe shell or inside hot air tobe expelled to the outside of the mainframe shell. By means oftemperature difference, heat is quickly dissipated from the CPU.

In addition to the aforesaid embodiments of the present invention,various modifications may be made thereunto. For example, in FIGS. 2-4,the keyboard and the LCD module may be removed, enabling the fan to blowair from the topside toward the bottom side or, from the left sidetoward the right side. The existence of the keyboard or LCD module inthe topside of the portable computer mainframe limits the upwardoperation direction of the fan. In general, the present inventionenables the user to selectively install the fan in different directionsto draw outside cooling air into the inside of the portable computermainframe from different sides.

Physically, the portable computer CPU cooling arrangement of the presentinvention enables the fan to be coupled between the head sink and eitherside of the mainframe shell to draw outside cooling air toward the heatsink in case the keyboard or LCD module is not provided above the CPU,enabling heat to be quickly carried away from the CPU.

Further, in the aforesaid CPU cooling arrangement, the fan can bedirectly mounted on either side of the mainframe shell to draw outsidecooling air toward the heat sink, enabling heat to be quickly carriedaway from the CPU.

Further, the CPU cooling arrangement can use the heat sink of either ofthe aforesaid second, third, fourth, and fifth embodiments, and the fancan be fastened to either open side of the heat sink. Alternatively,either of the sixth, seventh, and eighth embodiments can be used for theCPU cooling arrangement.

A prototype of portable computer CPU cooling arrangement has beenconstructed with the features of FIGS. 2-15. The portable computer CPUcooling arrangement functions smoothly to provide all of the featuresdiscussed earlier. Further, the heat sink and the cooling arrangementcan also be used in other electric apparatus to dissipate heat.

What the invention claimed is:
 1. A CPU cooling arrangement comprising amainframe holding a motherboard, said motherboard comprising a CPUsocket holding a CPU (central processing unit), a heat sink mounted onsaid CPU, and a fan mounted on said heat sink, wherein said motherboardis invertedly fixedly mounted inside said mainframe, holding said CPU,said heat sink, and said fan on a bottom sidewall of said motherboard;said mainframe comprises a bottom shell and an air hole disposed in saidbottom shell, said air hole facing said fan for enabling said fan todraw outside cooling air toward said heat sink for dissipation heat fromsaid CPU.
 2. The CPU cooling arrangement as claimed in claim 1 whereinsaid mainframe comprises a keyboard disposed at a topside thereof andformed of a metal frame, a circuit board, and a set of key switches, andsaid motherboard is fixedly fastened with the circuit board of saidkeyboard to said metal frame of said keyboard.
 3. The CPU coolingarrangement as claimed in claim 1 wherein said mainframe comprises aliquid crystal display module disposed at a topside thereof, saidmotherboard is fixedly fastened to a bottom sidewall of said liquidcrystal display module.
 4. The CPU cooling arrangement as claimed inclaim 1 wherein said mainframe comprises a protruded portion disposed insaid bottom shell around said air hole and adapted to receive said fan.5. The CPU cooling arrangement as claimed in claim 1 wherein said bottomshell of said mainframe is a flat shell.
 6. A CPU cooling arrangementmounted in a mainframe shell for computer and adapted to dissipate heatfrom a CPU (central processing unit), comprising: a heat sink mounted ona top sidewall of the CPU, said heat sink having a plurality ofperipheral sides, said peripheral sides including a plurality of closesides and two opposite open sides, said close sides including oneforming a contact base disposed in contact with said CPU, a plurality ofradiation fins respectively perpendicularly extended from said contactbase, and at least one convection trough defined between said radiationfins; a fan; and a wind box, said wind box comprising an inner wind holedisposed in one end thereof and coupled to one open side of said heatsink, an outer wind hole disposed in an opposite end thereof incommunication with a fan hole in said mainframe shell for computer, afan seat disposed in said outer wind hole and adapted to receive saidfan, and two mounting flanges respectively disposed at top and bottomsides of said outer wind hole, said mounting flanges each having atleast one screw hole respectively fastened to a respective screw hole ofsaid mainframe shell for computer with a respective tie screw.
 7. TheCPU cooling arrangement as claimed in claim 6 wherein said radiationfins of said heat sink are respectively perpendicularly connected tosaid CPU, and said heat sink having an extension part forming an airchannel.
 8. The CPU cooling arrangement as claimed in claim 6 whereinsaid wind box is formed integral with a part of said mainframe shellaround said fan hole.
 9. A CPU cooling arrangement comprising a heatsink and at least one fan, wherein said heat sink has six sides, saidsix sides including two opposite open sides for the mounting of said atleast one fan and four close sides, a contact base formed integral withone of said close sides, a plurality of radiation fins perpendicularlyextended from said contact base and arranged in parallel, said radiationfins each comprising a plurality of protruded portions and recessedportions, and at least one convection trough respectively definedbetween the protruded portions and recessed portions of said radiationfins, and wherein the four close sides of said heat sink include a closetopside having at least one air vent and one elongated slot disposed incommunication with said at least one convection trough.
 10. A CPUcooling arrangement comprising a mainframe, a motherboard mounted insidesaid mainframe, said motherboard having CPU socket, a CPU (centralprocessing unit) installed in said CPU socket, a heat sink mounted on atop sidewall of said CPU, and a fan mounted in said heat sink, whereinsaid fan is coupled between said heat sink and one sidewall of amainframe shell of said mainframe and adapted to draw cooling air fromthe outside of said mainframe toward said heat sink, and wherein saidheat sink has a plurality of peripheral sides, said peripheral sidesincluding a plurality of close sides and two opposite open sides, saidclose sides including one forming a contact base disposed in contactwith said CPU, a plurality of radiation fins respectivelyperpendicularly extended from said contact base, and at least oneconvection trough defined between said radiation fins.
 11. The CPUcooling arrangement as claimed in claim 10, wherein said radiation finsof said heat sink are respectively perpendicularly connected to saidCPU, and said heat sink having an extension part forming an air channel.12. The CPU cooling arrangement as claimed in claim 10, wherein saidwind box is formed integral with a part of said mainframe shell aroundsaid fan hole.